The link between companion dogs, human fertility rates, and social networks

The number of dogs in Western countries has increased over the past 2 decades, whereas the number of children has remained stable or decreased. Many dog owners, including those with children, say that their pets are more important to them than any human. Presumably, the declining fertility rates contribute to the increasing value of dogs in the lives of people, and dogs fill an empty niche. The companion-dog cultural-runaway theory posits that the change in dog-keeping habits has both biological and cultural evolutionary roots. Human ancestors developed a cooperative breeding system 2 million years ago, with the community aiding in child-rearing. Because people currently do not perceive the level of social support and trust to which they are biologically adapted, they seek alternatives. One coping strategy may involve transferring genetically based prosocial attitudes, such as the tendency to engage in parental behavior, to dogs. Western culture supports this shift and portrays dog ownership positively. Moreover, the biological evolution of dogs, with the spread of short-headed, small-sized lapdogs, also contributes to them being viewed as “children.” Dogs may facilitate or hinder the restoration of human network complexity, but this area is currently largely unexplored.